The invention relates to a method of and an apparatus for guiding a prosthesis, and more particularly, to such method and apparatus which utilizes an endoscope to insert a prosthesis or a tube into coeloma and to retain it at a given location therein.
When an opening of a bile duct into the duodenum undergoes a restriction, biliary secretion or pancreatic fluid may be prevented from flowing into the duodenum. This not only affects the digestion, but may cause jaundice, and hence, it has been the practice in the prior art to remove the restriction by a surgical operation. However, patients of an advanced age or who suffer from heart disease may not endure such operation. Recently, for those patients who are not amenable to such operation or where the restriction is caused by a temporary tumor which may be cured over a prolonged period of remedy, a remedy is attempted which utilizes an endoscope to place a cylindrical tube or prosthesis, formed of a synthetic resin material, into the affected part where the restriction has occurred, thus allowing the biliary secretion or pancreatic fluid to pass therethrough.
Such remedy will be briefly described with reference to FIGS. 1A to 1C. In FIG. 1A, there is shown an endoscope 1 including a forceps channel through which a guide wire 2 extends. The distal end 3 of the endoscope 1 is then inserted into coeloma. When the extremity 3a of the distal end 3 has reached an opening 4 of the duodenum, the guide wire 2 is push driven inward. The front end 2a of the guide wire 2 which projects forwardly from the extremety of the distal end is then forced into a restriction 5 to force it open until it completely extends through the restriction. A prosthesis 6 or a tube to be retained in place within the coeloma is then passed over the proximate end portion of the guide wire 2, followed by a pusher tube 7 which is utilized to drive the prosthesis inward. When the pusher tube 7 is driven inward, the prosthesis 6 moves along the guide wire 2 through the forceps channel of the endoscope 1 and reaches the location of the opening 4. As the pusher tube 7 is further driven inward, the prosthesis 6 is forced into the restriction 5 to force the walls of the restriction 5 apart, as shown in FIG. 1B. The inward drive applied to the pusher tube 7 ceases when the prosthesis has been inserted to a suitable position. The guide wire 2 is then withdrawn from the endoscope 1, and then the distal end 3 of the endoscope 1 is removed from the coeloma, thus leaving only the prosthesis 6 within the restriction 5. In this manner, biliary secretion or pancreatic fluid is allowed to flow through the prosthesis into the duodenum. In this manner, the risk involved with a surgical operation is avoided, and the pains caused to a patient are suppressed to a relatively low level.
However, the described remedy has a drawback in that the guide wire 2 must have a degree of rigidity which is required to allow it to be passed through the restriction 5. However, the rigidity or toughness may cause the front end 2a of the guide wire 2 to abut against the wall 8 of coeloma before it is passed through the restriction 5, as shown in FIG. 1C. Such abutment may cause the wall 8 to be injured by the front end 2a of the guide wire, and in worst cases, a risk arises that a hole may be pierced in the wall 8.